Longitudinal Study of Faecal Salmonella Shedding by Sows

Scientists in Italy report that young sows are more likely to shed Salmonella than older animals, that the post-weaning period is the high-risk period for excretion of Salmonella and that good biosecurity can reduce the Salmonella risk in weaned sows.

5 January 2012

3 minute read

By: Jackie Linden

Researchers at Istituto Zooprofilattico Sperimentale Umbria e Marche in Perugia, Italy, compared faecal excretion of Salmonella by sows of different parities and and at different stages of reproduction in a paper by Dr Chiara Magistrali and co-authors in Journal of Swine Health and Production.

They tested a total of 166 sows at two farrow-to-finish farms in Italy for Salmonella shedding at four stages of reproduction. Sows were divided into three groups: primiparous (farrowed one litter), multiparous (two to five litters), and old sows (>5 litters).

Faecal samples were collected approximately two weeks before parturition ('late gestation'), one and three weeks after parturition ('post-partum 1' and 'postpartum two'), and 30 to 60 days post-partum ('post-weaning'). Environmental samples were collected from farrowing rooms, farrowing crates and gestation pens before placement of sows.

The prevalence of Salmonella was 0.6 per cent in late gestation, 1.9 per cent in post-partum 1, 4.3 per cent in post-partum 2 and 26.5 per cent post-weaning, and 33.3 per cent in primiparous, 28.8 per cent multiparous, and 4.6 per cent in old sows.

Salmonella was isolated from environmental samples in farrowing rooms (eight per cent) and gestation pens (23 per cent).

Salmonella serovar Muenchen and Salmonella serovar Typhimurium were isolated both from sows and environmental samples on farm 1, while on farm 2, Salmonella serovar Choleraesuis and Salmonella enterica serovar 4,5,12:i- were identified in faecal samples, and Salmonella serovar 4,5,12:i and S. Typhimurium var Copenhagen were recovered from environmental samples.

Young sows are more likely to shed Salmonella than older animals, concluded Magistrali and co-authors, and that the post-weaning period is the high-risk period for excretion of Salmonella.

Environmental contamination and poor hygiene may play a role in the higher Salmonella risk in weaned sows, added the researchers. Their results suggest that environmental contamination could have played a major role in the epidemiology of Salmonella on these Italian farms, they reported. The environmental effect may be attributable to poorer management and hygiene in gestation rooms than in farrowing rooms. They explain that 'all-in, all-out' protocols were adopted for the farrowing rooms, while gestation pens were in a continuous flow.

Reference

Magistrali C.F., N. D'Avino, F. Ciuti, L. Cucco; C. Maresca, M. Paniccià, E. Scoccia, M. Tentellini and G. Pezzotti. 2011. Longitudinal study of fecal Salmonella shedding by sows. J. Swine Health Prod. 19(6):326–330.